PNP-Mn(I) Catalyzed Base Free N-Alkylation of Amines Using Alcohols.

We report a Mn(I) pincer complex, [Mn(CO)3{o-Ph2PC6H4C(O)N(C6H4PPh2-o)}κ3-P,N,P], bearing an amide-functionalized bisphosphine (BalaHariPhos), for the efficient N-alkylation of amines with alcohols. The reaction proceeds under base-free conditions at 80 °C, affording N-alkylated products in good to excellent yields within 12 h. Broad substrate scope is demonstrated, including the synthesis of indoles and dibenzyl piperazine. Selective mono-N-methylation of amines using methanol as a C1 source was also achieved. This work establishes a sustainable, non-noble metal platform for amine functionalization.